330 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



Taking the present observation together with those of Drude and 

 of Conrat it appears that the wave-length of a Hertz rectilinear is very 

 close to 2.10 times the length of the oscillator, provided the oscillator 

 is not less than two meters long and is of comparatively small diam- 

 eter. The influence of the diameter in determining the wave-length 

 was not tested further than by a single observation, in which it was 

 found that an oscillator made of two brass tubes, each 6 meters long 

 and 22 mm. in diameter, had a wave-length 2.14 times its length. 



TABLE II. 



Results obtained in Present Experiment. 



Comparison of the Result with Abrahams Theoretical Relation. — 

 The value obtained theoretically by Abraham, as a second approxima- 



